A man in his 30s was stabbed, while a man (55) also died at the house in Lisnaskea
The PSNI says it is treating attacks on two people in Fermanagh yesterday as murder and attempted murder.
A 51-year-old woman was found dead at a house in the Abbey Road area of Lisnaskea, near Enniskillen.
Officers say a man in his 30s, who was stabbed in the stomach, is in a stable condition in hospital.
A 55-year-old man also died at the house.
Police say they are not looking for anyone else in relation to the incident.
PSNI Detective Chief Inspector Eamon Corrigan said: “Post mortem examinations will be carried out in due course and at this stage we are working to establish the circumstances surrounding the incident.
"Although our enquiries are at an early stage, we are treating the death of the woman as murder."